The Android Open Source Project | e16cb84 | 2009-03-03 19:32:58 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include <ctype.h> |
| 18 | #include <dirent.h> |
| 19 | #include <errno.h> |
| 20 | #include <signal.h> |
| 21 | #include <stdio.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <unistd.h> |
| 24 | |
| 25 | #define MAX_LINE 512 |
| 26 | #define MAX_FILENAME 64 |
| 27 | |
| 28 | const char *EXPECTED_VERSION = "Latency Top version : v0.1\n"; |
| 29 | const char *SYSCTL_FILE = "/proc/sys/kernel/latencytop"; |
| 30 | const char *GLOBAL_STATS_FILE = "/proc/latency_stats"; |
| 31 | const char *THREAD_STATS_FILE_FORMAT = "/proc/%d/task/%d/latency"; |
| 32 | |
| 33 | struct latency_entry { |
| 34 | struct latency_entry *next; |
| 35 | unsigned long count; |
| 36 | unsigned long max; |
| 37 | unsigned long total; |
| 38 | char reason[MAX_LINE]; |
| 39 | }; |
| 40 | |
| 41 | static inline void check_latencytop() { } |
| 42 | |
| 43 | static struct latency_entry *read_global_stats(struct latency_entry *list, int erase); |
| 44 | static struct latency_entry *read_process_stats(struct latency_entry *list, int erase, int pid); |
| 45 | static struct latency_entry *read_thread_stats(struct latency_entry *list, int erase, int pid, int tid, int fatal); |
| 46 | |
| 47 | static struct latency_entry *alloc_latency_entry(void); |
| 48 | static void free_latency_entry(struct latency_entry *e); |
| 49 | |
| 50 | static void set_latencytop(int on); |
| 51 | static struct latency_entry *read_latency_file(FILE *f, struct latency_entry *list); |
| 52 | static void erase_latency_file(FILE *f); |
| 53 | |
| 54 | static struct latency_entry *find_latency_entry(struct latency_entry *e, char *reason); |
| 55 | static void print_latency_entries(struct latency_entry *head); |
| 56 | |
| 57 | static void signal_handler(int sig); |
| 58 | static void disable_latencytop(void); |
| 59 | |
| 60 | static int numcmp(const long long a, const long long b); |
| 61 | static int lat_cmp(const void *a, const void *b); |
| 62 | |
| 63 | static void clear_screen(void); |
| 64 | static void usage(const char *cmd); |
| 65 | |
| 66 | struct latency_entry *free_entries; |
| 67 | |
| 68 | int main(int argc, char *argv[]) { |
| 69 | struct latency_entry *e; |
| 70 | int delay, iterations; |
| 71 | int pid, tid; |
| 72 | int count, erase; |
| 73 | int i; |
| 74 | |
| 75 | delay = 1; |
| 76 | iterations = 0; |
| 77 | pid = tid = 0; |
| 78 | |
| 79 | for (i = 1; i < argc; i++) { |
| 80 | if (!strcmp(argv[i], "-d")) { |
| 81 | if (i >= argc - 1) { |
| 82 | fprintf(stderr, "Option -d expects an argument.\n"); |
| 83 | exit(EXIT_FAILURE); |
| 84 | } |
| 85 | delay = atoi(argv[++i]); |
| 86 | continue; |
| 87 | } |
| 88 | if (!strcmp(argv[i], "-n")) { |
| 89 | if (i >= argc - 1) { |
| 90 | fprintf(stderr, "Option -n expects an argument.\n"); |
| 91 | exit(EXIT_FAILURE); |
| 92 | } |
| 93 | iterations = atoi(argv[++i]); |
| 94 | continue; |
| 95 | } |
| 96 | if (!strcmp(argv[i], "-h")) { |
| 97 | usage(argv[0]); |
| 98 | exit(EXIT_SUCCESS); |
| 99 | } |
| 100 | if (!strcmp(argv[i], "-p")) { |
| 101 | if (i >= argc - 1) { |
| 102 | fprintf(stderr, "Option -p expects an argument.\n"); |
| 103 | exit(EXIT_FAILURE); |
| 104 | } |
| 105 | pid = atoi(argv[++i]); |
| 106 | continue; |
| 107 | } |
| 108 | if (!strcmp(argv[i], "-t")) { |
| 109 | if (i >= argc - 1) { |
| 110 | fprintf(stderr, "Option -t expects an argument.\n"); |
| 111 | exit(EXIT_FAILURE); |
| 112 | } |
| 113 | tid = atoi(argv[++i]); |
| 114 | continue; |
| 115 | } |
| 116 | fprintf(stderr, "Invalid argument \"%s\".\n", argv[i]); |
| 117 | usage(argv[0]); |
| 118 | exit(EXIT_FAILURE); |
| 119 | } |
| 120 | |
| 121 | if (tid && !pid) { |
| 122 | fprintf(stderr, "If you provide a thread ID with -t, you must provide a process ID with -p.\n"); |
| 123 | exit(EXIT_FAILURE); |
| 124 | } |
| 125 | |
| 126 | check_latencytop(); |
| 127 | |
| 128 | free_entries = NULL; |
| 129 | |
| 130 | signal(SIGINT, &signal_handler); |
| 131 | signal(SIGTERM, &signal_handler); |
| 132 | |
| 133 | atexit(&disable_latencytop); |
| 134 | |
| 135 | set_latencytop(1); |
| 136 | |
| 137 | count = 0; |
| 138 | erase = 1; |
| 139 | |
| 140 | while ((iterations == 0) || (count++ < iterations)) { |
| 141 | |
| 142 | sleep(delay); |
| 143 | |
| 144 | e = NULL; |
| 145 | if (pid) { |
| 146 | if (tid) { |
| 147 | e = read_thread_stats(e, erase, pid, tid, 1); |
| 148 | } else { |
| 149 | e = read_process_stats(e, erase, pid); |
| 150 | } |
| 151 | } else { |
| 152 | e = read_global_stats(e, erase); |
| 153 | } |
| 154 | erase = 0; |
| 155 | |
| 156 | clear_screen(); |
| 157 | if (pid) { |
| 158 | if (tid) { |
| 159 | printf("Latencies for thread %d in process %d:\n", tid, pid); |
| 160 | } else { |
| 161 | printf("Latencies for process %d:\n", pid); |
| 162 | } |
| 163 | } else { |
| 164 | printf("Latencies across all processes:\n"); |
| 165 | } |
| 166 | print_latency_entries(e); |
| 167 | } |
| 168 | |
| 169 | set_latencytop(0); |
| 170 | |
| 171 | return 0; |
| 172 | } |
| 173 | |
| 174 | static struct latency_entry *read_global_stats(struct latency_entry *list, int erase) { |
| 175 | FILE *f; |
| 176 | struct latency_entry *e; |
| 177 | |
| 178 | if (erase) { |
| 179 | f = fopen(GLOBAL_STATS_FILE, "w"); |
| 180 | if (!f) { |
| 181 | fprintf(stderr, "Could not open global latency stats file: %s\n", strerror(errno)); |
| 182 | exit(EXIT_FAILURE); |
| 183 | } |
| 184 | fprintf(f, "erase\n"); |
| 185 | fclose(f); |
| 186 | } |
| 187 | |
| 188 | f = fopen(GLOBAL_STATS_FILE, "r"); |
| 189 | if (!f) { |
| 190 | fprintf(stderr, "Could not open global latency stats file: %s\n", strerror(errno)); |
| 191 | exit(EXIT_FAILURE); |
| 192 | } |
| 193 | |
| 194 | e = read_latency_file(f, list); |
| 195 | |
| 196 | fclose(f); |
| 197 | |
| 198 | return e; |
| 199 | } |
| 200 | |
| 201 | static struct latency_entry *read_process_stats(struct latency_entry *list, int erase, int pid) { |
| 202 | char dirname[MAX_FILENAME]; |
| 203 | DIR *dir; |
| 204 | struct dirent *ent; |
| 205 | struct latency_entry *e; |
| 206 | int tid; |
| 207 | |
| 208 | sprintf(dirname, "/proc/%d/task", pid); |
| 209 | dir = opendir(dirname); |
| 210 | if (!dir) { |
| 211 | fprintf(stderr, "Could not open task dir for process %d.\n", pid); |
| 212 | fprintf(stderr, "Perhaps the process has terminated?\n"); |
| 213 | exit(EXIT_FAILURE); |
| 214 | } |
| 215 | |
| 216 | e = list; |
| 217 | while ((ent = readdir(dir))) { |
| 218 | if (!isdigit(ent->d_name[0])) |
| 219 | continue; |
| 220 | |
| 221 | tid = atoi(ent->d_name); |
| 222 | |
| 223 | e = read_thread_stats(e, erase, pid, tid, 0); |
| 224 | } |
| 225 | |
| 226 | closedir(dir); |
| 227 | |
| 228 | return e; |
| 229 | } |
| 230 | |
| 231 | static struct latency_entry *read_thread_stats(struct latency_entry *list, int erase, int pid, int tid, int fatal) { |
| 232 | char filename[MAX_FILENAME]; |
| 233 | FILE *f; |
| 234 | struct latency_entry *e; |
| 235 | |
| 236 | sprintf(filename, THREAD_STATS_FILE_FORMAT, pid, tid); |
| 237 | |
| 238 | if (erase) { |
| 239 | f = fopen(filename, "w"); |
| 240 | if (!f) { |
| 241 | if (fatal) { |
| 242 | fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno)); |
| 243 | fprintf(stderr, "Perhaps the process or thread has terminated?\n"); |
| 244 | exit(EXIT_FAILURE); |
| 245 | } else { |
| 246 | return list; |
| 247 | } |
| 248 | } |
| 249 | fprintf(f, "erase\n"); |
| 250 | fclose(f); |
| 251 | } |
| 252 | |
| 253 | f = fopen(GLOBAL_STATS_FILE, "r"); |
| 254 | if (!f) { |
| 255 | if (fatal) { |
| 256 | fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno)); |
| 257 | fprintf(stderr, "Perhaps the process or thread has terminated?\n"); |
| 258 | exit(EXIT_FAILURE); |
| 259 | } else { |
| 260 | return list; |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | e = read_latency_file(f, list); |
| 265 | |
| 266 | fclose(f); |
| 267 | |
| 268 | return e; |
| 269 | } |
| 270 | |
| 271 | static struct latency_entry *alloc_latency_entry(void) { |
| 272 | struct latency_entry *e; |
| 273 | |
| 274 | if (free_entries) { |
| 275 | e = free_entries; |
| 276 | free_entries = free_entries->next; |
| 277 | } else { |
| 278 | e = calloc(1, sizeof(struct latency_entry)); |
| 279 | if (!e) { |
| 280 | fprintf(stderr, "Could not allocate latency entry: %s\n", strerror(errno)); |
| 281 | exit(EXIT_FAILURE); |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | return e; |
| 286 | } |
| 287 | |
| 288 | static void free_latency_entry(struct latency_entry *e) { |
| 289 | e->next = free_entries; |
| 290 | free_entries = e; |
| 291 | } |
| 292 | |
| 293 | static struct latency_entry *find_latency_entry(struct latency_entry *head, char *reason) { |
| 294 | struct latency_entry *e; |
| 295 | |
| 296 | e = head; |
| 297 | |
| 298 | while (e) { |
| 299 | if (!strcmp(e->reason, reason)) |
| 300 | return e; |
| 301 | e = e->next; |
| 302 | } |
| 303 | |
| 304 | return NULL; |
| 305 | } |
| 306 | |
| 307 | static void set_latencytop(int on) { |
| 308 | FILE *f; |
| 309 | |
| 310 | f = fopen(SYSCTL_FILE, "w"); |
| 311 | if (!f) { |
| 312 | fprintf(stderr, "Could not open %s: %s\n", SYSCTL_FILE, strerror(errno)); |
| 313 | exit(EXIT_FAILURE); |
| 314 | } |
| 315 | |
| 316 | fprintf(f, "%d\n", on); |
| 317 | |
| 318 | fclose(f); |
| 319 | } |
| 320 | |
| 321 | static void erase_latency_file(FILE *f) { |
| 322 | fprintf(f, "erase\n"); |
| 323 | } |
| 324 | |
| 325 | static struct latency_entry *read_latency_file(FILE *f, struct latency_entry *list) { |
| 326 | struct latency_entry *e, *head; |
| 327 | char line[MAX_LINE]; |
| 328 | unsigned long count, max, total; |
| 329 | char reason[MAX_LINE]; |
| 330 | |
| 331 | head = list; |
| 332 | |
| 333 | if (!fgets(line, MAX_LINE, f)) { |
| 334 | fprintf(stderr, "Could not read latency file version: %s\n", strerror(errno)); |
| 335 | exit(EXIT_FAILURE); |
| 336 | } |
| 337 | |
| 338 | if (strcmp(line, EXPECTED_VERSION) != 0) { |
| 339 | fprintf(stderr, "Expected version: %s\n", EXPECTED_VERSION); |
| 340 | fprintf(stderr, "But got version: %s", line); |
| 341 | exit(EXIT_FAILURE); |
| 342 | } |
| 343 | |
| 344 | while (fgets(line, MAX_LINE, f)) { |
| 345 | sscanf(line, "%ld %ld %ld %s", &count, &total, &max, reason); |
| 346 | if (max > 0 || total > 0) { |
| 347 | e = find_latency_entry(head, reason); |
| 348 | if (e) { |
| 349 | e->count += count; |
| 350 | if (max > e->max) |
| 351 | e->max = max; |
| 352 | e->total += total; |
| 353 | } else { |
| 354 | e = alloc_latency_entry(); |
| 355 | e->count = count; |
| 356 | e->max = max; |
| 357 | e->total = total; |
| 358 | strcpy(e->reason, reason); |
| 359 | e->next = head; |
| 360 | head = e; |
| 361 | } |
| 362 | } |
| 363 | } |
| 364 | |
| 365 | return head; |
| 366 | } |
| 367 | |
| 368 | static void print_latency_entries(struct latency_entry *head) { |
| 369 | struct latency_entry *e, **array; |
| 370 | unsigned long average; |
| 371 | int i, count; |
| 372 | |
| 373 | e = head; |
| 374 | count = 0; |
| 375 | while (e) { |
| 376 | count++; |
| 377 | e = e->next; |
| 378 | } |
| 379 | |
| 380 | e = head; |
| 381 | array = calloc(count, sizeof(struct latency_entry *)); |
| 382 | if (!array) { |
| 383 | fprintf(stderr, "Error allocating array: %s\n", strerror(errno)); |
| 384 | exit(EXIT_FAILURE); |
| 385 | } |
| 386 | for (i = 0; i < count; i++) { |
| 387 | array[i] = e; |
| 388 | e = e->next; |
| 389 | } |
| 390 | |
| 391 | qsort(array, count, sizeof(struct latency_entry *), &lat_cmp); |
| 392 | |
| 393 | printf("%10s %10s %7s %s\n", "Maximum", "Average", "Count", "Reason"); |
| 394 | for (i = 0; i < count; i++) { |
| 395 | e = array[i]; |
| 396 | average = e->total / e->count; |
| 397 | printf("%4lu.%02lu ms %4lu.%02lu ms %7ld %s\n", |
| 398 | e->max / 1000, (e->max % 1000) / 10, |
| 399 | average / 1000, (average % 1000) / 10, |
| 400 | e->count, |
| 401 | e->reason); |
| 402 | } |
| 403 | |
| 404 | free(array); |
| 405 | } |
| 406 | |
| 407 | static void signal_handler(int sig) { |
| 408 | exit(EXIT_SUCCESS); |
| 409 | } |
| 410 | |
| 411 | static void disable_latencytop(void) { |
| 412 | set_latencytop(0); |
| 413 | } |
| 414 | |
| 415 | static void clear_screen(void) { |
| 416 | printf("\n\n"); |
| 417 | } |
| 418 | |
| 419 | static void usage(const char *cmd) { |
| 420 | fprintf(stderr, "Usage: %s [ -d delay ] [ -n iterations ] [ -p pid [ -t tid ] ] [ -h ]\n" |
| 421 | " -d delay Time to sleep between updates.\n" |
| 422 | " -n iterations Number of updates to show (0 = infinite).\n" |
| 423 | " -p pid Process to monitor (default is all).\n" |
| 424 | " -t tid Thread (within specified process) to monitor (default is all).\n" |
| 425 | " -h Display this help screen.\n", |
| 426 | cmd); |
| 427 | } |
| 428 | |
| 429 | static int numcmp(const long long a, const long long b) { |
| 430 | if (a < b) return -1; |
| 431 | if (a > b) return 1; |
| 432 | return 0; |
| 433 | } |
| 434 | |
| 435 | static int lat_cmp(const void *a, const void *b) { |
| 436 | const struct latency_entry *pa, *pb; |
| 437 | |
| 438 | pa = (*((struct latency_entry **)a)); |
| 439 | pb = (*((struct latency_entry **)b)); |
| 440 | |
| 441 | return numcmp(pb->max, pa->max); |
| 442 | } |